Several new areas of development and application of the dynamic nmr (nuclear magnetic resonance) chemical exchange probe of the active site of enzymes will be explored. We hope to provide a novel experimental method for probing the structure of the transition state enzyme complex by studying the nmr spectra of transition-state analogs as they reversibly bind the enzyme active site. By also applying these techniques to substrate analogs, it should be possible to achieve a detailed understanding of the enzymatic mechanism of action. In addition, an nmr chemical exchange method for the study of covalent substrate intermediates will be presented. This should provide answers as to whether a covalent intermediate does, in fact, exist and, most importantly, the amino acid residue at the active site which covalently links to the substrate or substrate analog. These nmr techniques will be applied to the study of ribonuclease A, alpha-chymotrypsin, 3', 5'-cyclic-AMP-dependent protein kinase, phosphoglycerate mutase and nucleotide phosphotransferase. However, broad application of these ideas to other enzymes are anticipated as well.